Process design controllability

The first chapter in this section provides a unique account of the ecology, i.e. distribution, survival and life-style, of microorganisms in the factory environment, and should enable process designers, controllers and quality control personnel to comprehend, trace and eradicate the sources of failure due to extraneous microbial contaminants in the finished product. Much of the information given here is applicable to hospital manufacture also, and this is extended in a contribution (Chapter 19) dealing with contamination in hospital pharmaceutical products and in the home. 

Cheryl L. Jennings, PhD, is Vice-President of Process Design and Improvement, and Six Sigma Black Belt at Bank of America. Her interests are in the application of statistical methods to process design, control, and improvement. 

Special safety constraints apply to equipment selection, design, and operation in nuclear reprocessing (269). Equipment should be reHable and capable of remote control and operation for long periods with minimal maintenance. Pulsed columns and remotely operated mixer—settlers are commonly used (270). The control of criticaHty and extensive monitoring of contamination levels must be included in the process design. 

The problems of monomer recovery, reaction medium viscosity, and control of reaction heat are effectively dealt with by the process design of Montedison Fibre (53). This process produces polymer of exceptionally high density, so although the polymer is stiU swollen with monomer, the medium viscosity remains low because the amount of monomer absorbed in the porous areas of the polymer particles is greatly reduced. The process is carried out in a CSTR with a residence time, such that the product k jd x. Q is greater than or equal to 1. is the initiator decomposition rate constant. This condition controls the autocatalytic nature of the reaction because the catalyst and residence time combination assures that the catalyst is almost totally expended in the reactor. 

For optimisation of process design and process control, the efficiency and effectiveness of the various methods depend on the process being modeled and the process modeling software that is used. 

DATTA-BARUA Natural Gas Measurement and Control DEAN Lange s Handbook of Chemistry, Fourteenth Edition DESHOTELS, ZIMMERMAN Cost-Effective Risk Assessment for Process Design... 

Bioprocess Control An industrial fermenter is a fairly sophisticated device with control of temperature, aeration rate, and perhaps pH, concentration of dissolved oxygen, or some nutrient concentration. There has been a strong trend to automated data collection and analysis. Analog control is stiU very common, but when a computer is available for on-line data collec tion, it makes sense to use it for control as well. More elaborate measurements are performed with research bioreactors, but each new electrode or assay adds more work, additional costs, and potential headaches. Most of the functional relationships in biotechnology are nonlinear, but this may not hinder control when bioprocess operate over a narrow range of conditions. Furthermore, process control is far advanced beyond the days when the main tools for designing control systems were intended for linear systems. 

As a result of these poorly designed control systems, users experience significant operational problems, including machine and process shutdowns. As with any process plant, the first objective is to achieve reliable production from the FCCU. Only with reliable production will operators start optimizing the unit. Users, therefore, are not using the... 

The principal technological developments in the control of air pollution by engineering during the nineteenth century were the stoker for mechanical firing of coal, the scrubber for removing acid gases from effluent gas streams, cyclone and bag house dust collectors, and the introduction of physical and chemical principles into process design. 

Liaison with Control Engineering Department on Plant and Process Design... 

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